revert: temporarily restore content to the last Play-Store-compatible state

The live Play Store release (wallet-android 85bde7e, published 2026-06-15)
was built against whatever was on this branch's HEAD at the time - which,
since master had received no commits between 2026-03-02 and this week, was
commit 7a087cf. This week's changes (nova-base sync, Tron config/icons,
balance test fixtures, etc.) are real and wanted, but they've made master
incompatible with that still-live app version, and live users installing
fresh right now get a completely empty tokens list because of it (the app's
chain sync silently fails whole-hog on any single malformed/incompatible
chain entry, leaving new installs with zero locally-cached chains).

This makes master's served content match 7a087cf exactly, stopping the
bleeding for current live users without needing an emergency app release.
None of this week's work is lost - it's all preserved on
pending/post-fix-release and will come back once wallet-android's Tron
send feature is complete and both repos can ship together in one
coordinated release.

icons/chains/gradient/Tron.svg

@@ -1,10 +0,0 @@
-<svg width="48" height="48" viewBox="0 0 48 48" fill="none" xmlns="http://www.w3.org/2000/svg">
-<path d="M0 14C0 6.26801 6.26801 0 14 0H34C41.732 0 48 6.26801 48 14V34C48 41.732 41.732 48 34 48H14C6.26801 48 0 41.732 0 34V14Z" fill="url(#paint0_linear_tron)"/>
-<path fill-rule="evenodd" clip-rule="evenodd" d="M13 15.5L24.5 13L35 16.7L24.9 27.9L13 15.5ZM24.1 30.1L33.6 18.7L25.5 30.9L24.1 30.1ZM22.8 30.9L14.4 17L23 26.3L22.8 30.9Z" fill="white"/>
-<defs>
-<linearGradient id="paint0_linear_tron" x1="0" y1="0" x2="48" y2="48" gradientUnits="userSpaceOnUse">
-<stop stop-color="#FF3B30"/>
-<stop offset="1" stop-color="#B8001F"/>
-</linearGradient>
-</defs>
-</svg>